1. Field of the Invention
The present invention relates to amorphous alloys which possess excellent characteristics for electrode materials in electrolysis of aqueous solutions of alkali halides.
2. Description of the Prior Arts
It has been known to use electrodes made of corrosion resistant metals such as titanium coated with noble metals. However, when such electrodes are used as an anode in the electrolysis of aqueous solutions of sodium chloride, coated noble metals are severely corroded and sometimes peeled off from the titanium substrate. It is, therefore, difficult to use these electrodes for industrial processes.
On the other hand, modern chlor-alkali industries are using composite oxide electrodes consisting of corrosion resistant metals as a substrate on which composite oxides such as ruthenium oxide and titanium oxide are coated. When these electrodes are used as an anode in the electrolysis of sodium chloride solutions, they possess the following disadvantages; the composite oxides are sometimes peeled off from the metal substrate and chlorine gas produced are contaminated by a relatively large amount of oxygen. In addition, the corrosion resistance of the electrodes is not sufficiently high, particularly at low pH.
In general, ordinary alloys are crystalline in the solid state. However, rapid quenching of some alloys with specific compositions from the liquid state gives rise to solidification in the amorphous structure. These alloys are called amorphous alloys.
The amorphous alloys have significantly high mechanical strength in comparison with the conventional industrial alloys. Some amorphous alloys with specific compositions have extremely high corrosion resistance which cannot be obtained in ordinary crystalline alloys.